Siloxane polymerization in gypsum wallboard

Abstract

A method of making a gypsum board including: preparing an aqueous slurry including a mixture of: calcium sulfate hemihydrate, water at a weight ratio of water to calcium sulfate hemihydrate of 0.2:1 to 1.2:1, and on a dry basis per 100 parts by weight (pbw) calcium sulfate hemihydrate: 0.2 to 2 pbw siloxane, 0.01 to 2 pbw siloxane polymerization catalyst including magnesium oxide and optionally fly ash, and 0.01 to 0.2 pbw triethanolamine (TEOA); allowing the siloxane to polymerize to polysiloxane; and depositing the slurry on a first cover sheet and covering the slurry with a second cover sheet to shape the slurry, and allowing the shaped slurry to set to form the gypsum board. Also, disclosed is the gypsum board resulting from the method.

Dependencies are inferred from the claim text.